/**
 * Created by zhangjinrui on 17/6/27.
 */

public class Solution24 {

    public static void main(String args[]){
        Solution24 s = new Solution24();
    }

    public ListNode swapPairs(ListNode head) {
        ListNode cur = head;
        ListNode f;
        ListNode start;
        while(true){
            if(cur.next == null){
                break;
            }
            f = cur.next.next;

        }
        return null;
    }

    public ListNode swapTwo(ListNode a, ListNode b){
        ListNode f = b;
        b.next = a;
        a.next = b;
        return null;
    }

}
